The objective of this research project is to extend previous studies of the cytogenetics of human tumors by the use of recently developed cytogenetic techniques. Different Giemsa staining of heterochromatin and quinacrine fluorescence will be used for chromosome analysis of hematologic malignancies and solid tumors. Special attention will be given to determination of the origin of marker chromosomes in tumors reported to contain similar marker chromosomes such as testicular tumors and the double minutes (centric fragments) in some childhood and central nervous system tumors.